I wonder, however, why we need to speak about “redeeming” culture at all? T. M. Moore appeals to Eph 4:8, but the difficulty of this appeal is that the context is all about the visible, institutional church. Paul isn’t talking about “common grace” (the providential distribution of common, creational gifts). He’s talking about the consequences of the ascension for the church. That much seems clear from the context.
More generally, however, is not speaking of “redeeming” culture a confusion of categories? Creation isn’t sinful per se. Culture (e.g., music, language) belongs to creation, not grace. To be sure Reformed theology says that grace renews nature meaning that people, sinners, are redeemed and they do live in culture and participate in it. If we take language as an element of culture, why does language need to be “redeemed”? Did Jesus die for language? Did language sin? No, humans sin. Humans need to be come to see, by grace, that language is a common gift, and they need to use it appropriately, wisely, and godly but I think it’s not helpful to speak of “redeeming” culture.
More profoundly, I worry that this indiscriminate use of the verb “to redeem” cheapens it. If it applies to everything (culture) then how is real redemption all that significant? In Rom 8:23 Paul does speak of the “redemption” of our bodies but he does so in a soteric, not cultural context. He’s not saying, “we need to redeem our bodies by doing x or y.” He’s talking about the resurrection or the consummation (which it is doesn’t matter for the purposes of this argument).
We see the same association in 1 Cor 1:30. The semantic range of the λυτρον and λυω related words has little to do with creation or culture and much more to do with grace and renewal. Paul isn’t interested in “redeeming” Greek or “redeeming” tentmaking or “redeeming” politics or any of those things. He’s interested in the redemption of sinners and in the metaphorical buying back (for which Paul used a different stem and arguably a slightly different idea) of time (Eph 5:16), in the service of Christ.
The appeal to Eph 4:8 and the lack of solid NT support for this way of speaking (“redeeming the culture”) also signals that this way of speaking is not really driven by biblical exegesis and, as far as I know, it isn’t driven by our confessions or our classical theologians.
Why not speak of “engaging” the culture or “applying revelational norms” or “natural law” or “creational law” to the culture? When people abuse a culture or develop a wicked culture it is contrary to law not grace. What is there about any given facet of a culture that requires it to be redeemed? I fear that when we speak this way we testify that we think that culture is inherently dirty and in need of sanctification, in other words, I wonder if there isn’t embedded in this way of thinking a quasi-gnostic dis-ease with creation? Perhaps not, but I do wonder.